5 Ways to Decrease the Risk for an ACL Injury

Injuries to the Anterior Cruciate Ligament (ACL) are some of the most common injuries in the active population. As incidence of other injuries have decreased, injuries involving the ACL have rose astronomically over the years.  There have been numerous studies done looking at what causes the ACL to tear. More specifically, female athletes are 4-5x more likely to tear their ACL as compared to their male counterparts.

Like with any injury, it cannot be blamed on one thing. Injuries are multi-factorial as well as non-preventable.  Injuries will always happen.  The only thing that we can do is to decrease the frequency or incidence of them. Luckily, as we continue to learn more about the mechanism of injury, we have developed some strategies to reduce your chance of ACL injuries.

 

5 Ways to Decrease the Risk for an ACL Injury

Here are 5 things to focus on when designing programs to reduce ACL injuries.

 

Optimize Mobility

If you look at the human body, there are many joints. Some of those joints require mobility and some of those joints require stability. Depending on which plane of motion you are in, mobility or stability is usually more imperative than the other.

When it comes to mobility, there are certain joints in the body that we need to have optimal mobility in order to decrease the risk for an injury to the ACL. The two joints that come to mind are the talocrural joint of the ankle, and the femoroacetabular joint of the hip.

For the ankle, specifically dorsiflexion range of motion is imperative to decrease strain at the knee. If the ankle doesn’t have the ability to dorsiflex and absorb force during a land from a jump or cutting maneuver, the mid foot or knee are the two joints that will have to have increased mobility to accommodate the athletic endeavor.

 

Ankle Mobility

To assess for adequate ankle mobility, use the Knee to Wall Ankle Mobility Test.

Key Points:

  • Place your foot 4 inches away.
  • Keeping your foot flat on the floor, attempt to touch your knee to the wall.
  • Don’t allow for valgus or varus collapse.

If you can reach the wall from 4 inches, then you have sufficient ankle mobility to run, squat, and perform without playing increased stress through the knee due to poor ankle mobility.

The other joint in the body that needs to have optimal mobility is the hip.  The motions at the hip that need adequate mobility are hip flexion, hip extension, hip abduction, hip internal and external rotation.

Now, you may be saying, “Wow, that’s a lot of areas that need mobility.”  Well, let’s break it down!

 

Hip Flexion

5 ways to reduce ACL injuriesAnecdotally, I like to see clients present with full hip flexion. If there is decreased mobility into hip flexion, this can send a signal to the brain to alter movement and muscle firing patterns and in turn, can affect how someone lands or moves.

A quick and easy test is to test passive hip flexion range of motion.  

This involves bringing your knee towards your chest. Ideally, your thigh should reach the inferior aspect of your rib cage. Now, everyone is made differently and depending upon what sport you play, hip structure can vary from person to person.

If you cannot reach your thigh to your rib cage, slightly abduct your thigh and see if you can go further. If you can, then your hips are structured a little differently.

 

Hip Extension

Key Points:

  • Thigh should be able to reach parallel to ground.
  • Knee should be at 90 degrees to thigh.
  • Thigh should drop straight down and not flare out towards side of body.

Hip extension mobility is necessary to be able to activate the gluteus maximus and hamstrings in order to decrease incidence of a valgus collapse. If adequate hip extension mobility is not present, then muscular compensation will occur and in turn, possible injury.

 

Hip Internal Rotation (IR)

Even though hip internal rotation is part of the combination of movements that contribute to an ACL injury, not having the requisite mobility is a risk factor. If the body doesn’t have certain available ranges of motion, then the brain and central nervous system are not able to prevent going into those said ranges of motion. Therefore, if someone doesn’t have adequate hip internal rotation, then the body has no way to prevent that motion from occurring.

VandenBerg et al. in Arthroscopy: The Journal of Arthroscopic & Related Surgery that “risk of ACL injury is associated with restricted hip IR, and as hip IR increases, the odds of having an ACL tear decreases.”

 

Hip External Rotation

Hip external rotation is important because avoidance of a knee valgus position is necessary to avoid injury to the ACL. Having adequate hip external range of motion will allow the athlete to be able to get into an athletic position to avoid that valgus position.

 

Learn How to Land

You watch any NFL or NBA game and guys are jumping to catch a ball to to tap in a rebound for 2 points. Most injuries to the ACL don’t occur on the jumping portion as it does on the landing portion.

When athletes have to land from a jump, the body has to absorb 7-10x their body-weight in forces from the ground.  If joints aren’t in an ideal position to absorb and adapt to stress, injuries can happen.

landing mechanics ACL injury

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Therefore, we need to assess athletes in their landing patterns and mechanics to make sure their body is resilient and capable to land properly.

 

Step Down Test

 

The Step Down Test is a simple way to determine an athlete’s predisposition to absorbing eccentric stress. Ideally, we like to see the pelvis, hip, knee, and ankle remain in a line during descent.

 

If someone steps down and the femur internally rotates and the knee goes into valgus collapse,  this is something that needs to be rectified.

If you want to use a more quantitative analysis of landing mechanics and skill as compared to the contralateral limb, then here are 3 tests that can help with that.

 

Single Leg Hop for Distance

Key Points:

  • Instruct the athlete to jump as far as then can and land on 1 leg.
  • They must stick the landing without hopping around or using their leg/arm for balance.
  • Perform 2 trials.  Measure each jump, take the average of the 2 trials, then repeat on the opposite leg.

 

Triple Hop for Distance

Key Points:

  • Instruct the athlete to jump as far as they can, land on 1 leg, and continue for 2 more hops, sticking the 3rd landing
  • They must stick the landing without hopping around or using their leg/arm for balance.
  • Perform 2 trials.  Measure each jump, take the average, then repeat on the opposite leg.

 

Crossover Hop for Distance

Key Points:

  • Instruct the athlete to jump as far as they can, land on 1 leg, and continue for 2 more hops, sticking the 3rd landing while crossing over a tape line on the floor with each jump.
  • They must stick the landing without hopping around or using their leg/arm for balance.
  • Perform 2 trials.  Measure each jump, find the average, then repeat on the opposite leg.

Now that you have the average for all 3 jumps, we need to determine if the difference between the two limbs is significant. According to Adams in the Journal of Orthopaedic and Sports Physical Therapy, limb symmetry indexes of 90% have previously been suggested as the milestone for determining normal limb symmetry in quadriceps strength and functional testing.

According to Phil Plisky, one of the developers of the Y-Balance Test, he advocates that the athlete’s reconstructed lower extremity be within 95% on the non-involved leg.

To determine if distances hopped are significant, the involved limb must be within 90-95% of the non-involved side. If it is less than 90%, then that athlete is at risk for future knee injury.

Using a regimen consisting of single leg plyometrics in the sagittal, frontal, and transverse planes as well as single leg exercises that focus on power development can help to improve any major deficits.

 

Achieve Symmetry

If an athlete presents with a gross asymmetry, their risk for injury can increase 3-17x. Besides using the Hop Tests, one way to assess gross asymmetry is also using the Y-Balance Test.

The Y-Balance Test consists of 3 lower and upper body movements. For the sake of this post, we will be focusing on the lower body. The movements consist of:

y balance test ACL injuries

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If there is greater than a 4 cm difference right vs left on the anterior reach (1st picture), this is considered a risk factor for a lower extremity injury.

Smith, Chimera, and Warren found in Medicine and Science in Sports & Exercise that “ANT (anterior)  asymmetry >4 cm was associated with increased risk of noncontact injury.”

If there is greater than a 6 cm difference right vs left on the posteromedial or posterolateral reaches, pictures 2 and 3, then this is considered a risk factor for a lower extremity injury.

Asymmetry is a normal thing.  Everyone from elite level athletes to the average joe has natural asymmetries right vs left. Some asymmetries may not change and some asymmetries may make someone the elite level athlete that they are. Having a relative asymmetry right vs left is ok, but having a gross asymmetry is not.

 

Enhance Core Stability

The core musculature is responsible for providing a stable base for the pelvis, hips, knees, ankles, etc. to function off of in life and in sport. If a stable base is not provided, then it can create instability and injury further down or up the kinetic chain.

Decreased core stability can cause:

  • Pelvic Drop
  • Femoral Internal Rotation
  • Knee Valgus
  • Tibial External Rotation
  • Subtalar Excessive Pronation

All these movements are associated with injuries of the ACL. By stabilizing proximally and providing a stable base for all of the aforementioned areas to work off of, this can decrease the risk for injury.

In order to test for core stability, the Trunk Stability Push-Up (TSPU) by Functional Movement is a good test.

This is a great test to determine if someone can maintain a neutral spine while performing a push-up, but also to determine if they have a base level of core stability to maintain a certain trunk position during life/sport.

If someone cannot maintain a specific trunk position, this doesn’t mean that they have a “weak core.” or weak upper extremities. It means that the athlete doesn’t have the capability to stabilize their core proximally in order to exude force distally.

 

Learn How to Decelerate

Most athletes are fast or at least quick on their feet. The great athletes can speed up and slow down better than anyone. One common risk factor we see with ACL injuries is the inability or subpar ability to be able to decelerate.

What this means is that if someone is going to stop or change direction, they need to have the necessary skills to control their body in space when going from accelerating, to decelerating, and then back to accelerating again.

All fast cars are fast! All really fast cars have great brakes!

In order to assess an athlete’s ability to decelerate, observe how the do with change of direction drills.  For example, movements such as:

 

Sprint/Backpedal w/ Redirection

Lateral Shuffles w/ Redirection

Sprint with 45 Degree Cut

Sprint with 90 Degree Cut

Backpedal, Stop, to 90 Degree Sprint

Backpedal, Stop, to 45 Degree Sprint

All of these various movements test an athlete’s ability to accelerate, decelerate and change directions in all planes of movement. A coach, personal trainer, or physical therapist should be present to provide the athlete with the redirection component. This makes it more random and unpredictable to make sure the athlete can react and move appropriately.

While observing these various change of direction movements, observe the mechanics of the pelvis and lower extremity.

Does the pelvis and hip/knee stay in a relative stable and neutral position when decelerating and stopping?

Does the pelvis and hip/knee go into a valgus collapse during decelerating, stopping, and accelerating phases of movement? Compare these right versus left lower extremities.

If you are having trouble observing these things with the naked eye, film it!  There are apps such as DartFish or Hudl that you can download to film athletes and then you can watch it in slow motion to observe any differences side to side.

If differences are seen in right and left comparison, then work on change of direction drills. When first starting off, start the athlete at ½ or ¼ speed so that they can work on their deceleration, stopping, and accelerating mechanics.

We don’t necessarily want to bombard the athlete with too much information about biomechanics of the lower extremity, but having a basic discussion with them and showing them how they currently move and how you would want them to move safely and more efficiently is ideal.

Then once, then can master ¼ or ½ speed, then increase the speed of the drills until you are working at full speed on both sides. There are a multitude of drills out there to work on acceleration, deceleration, stopping, and change of direction. Make sure start with the sagittal plane, and then progress into the frontal and transverse planes.  

If you can’t master the sagittal plane, then the frontal and transverse planes will be much more challenging.

Assessing mobility, landing mechanics, relative lower extremity symmetry, core stability, and acceleration/deceleration can all help to improve an athlete’s performance as well as decrease their risk for an ACL injury.

 

About the Author

Andrew Millett is a Boston-based physical therapist in the field of orthopedic and sports medicine physical therapy.  He helps to bridge the gap between physical therapy and strength and conditioning.  Visit his website at AndrewMillettPT.com.

 

 

 

Meniscus Repair Rehabilitation: Why Are We Still Stuck in the 90’s?

Meniscus injuries within the knee are a common occurrence.  In fact, the National Center for Health Statistics reports that meniscus surgery is the most frequent surgical procedure performed by orthopedic surgeons in the United States, with more than 50% of the procedures performed in patients 45 years of age or older.

Despite this high occurrence, many inconsistencies continue to exist in the rehabilitation of a patient following meniscus repair surgery, particularly involving the rate of weightbearing and range of motion.

I’m still shocked by this and wanted to discuss the recent research that is lending to a more progressive approach to return people safely back to their prior level of function.

Rehabilitation Follow Meniscus Repair

meniscus repair surgery weightbearingRehabilitation after surgical debridement of the meniscus is pretty straightforward. We return the patient’s range of motion, strength and function per their symptoms and let pain and swelling guide the rehab process (a very general guide but one often employed by many rehabilitation specialists).

However, when the meniscus is actually repaired and not just debrided, there are other factors to consider.  When a meniscus is repaired, the tear is approximated using stitches to allow the tear to heal.  

Rehabilitation following a meniscus repair has to be more conservative, however, despite research saying otherwise, there are still many rehabilitation protocols floating around the orthopaedic and sports medicine world that recommend limiting weight-bearing and range of motion after a meniscal repair.  We continue to ignore the literature because of fear that the ‘stress’ on the meniscus with walking and range of motion may be too high.

Unfortunately, many of these commonly used protocols are from the 1990’s. (The current protocols we use can be found at RehabilitationProtocols.com)

So if we’re going to talk 90’s protocols, take a look at these studies from way back when from Shelbourne  and Barber  that showed excellent results in patients undergoing a combined ACL-meniscus repair procedure and utilizing no limitations in weightbearing or range of motion, similar to a protocol for an isolated ACL reconstruction.

Recent studies from VanderHave and Lind on isolated meniscus repairs have shown similar results using an “aggressive” program of immediate weightbearing compared to a more conservative approach.

I certainly wouldn’t consider these “aggressive” programs, they simply used immediate weightbearing and range of motion.

Again, these studies show meniscal repair outcomes are no different while using restricted weightbearing and range of motion versus an “aggressive” protocol of immediate weight-bearing and unlimited range of motion.

Early Weightbearing After Meniscus Repair

meniscus repair surgery range of motionBut what about the exact mechanisms that many are still fearful of allowing early in the process, like early walking and range of motion? Won’t that put the repair in a position to fail?

We typically immobilize people in full extension during weightbearing, locked in a brace for 4-6 weeks after meniscal repair surgery.

So, if immobilized in extension, why do we limit weightbearing?

During weightbearing, compressive forces are loaded across the menisci. These tensile forces create ‘hoop stresses’, which expand the menisci in extension. These hoop stresses are thought to be helping the healing process in many tears by approximating the tissue.

Furthermore, the compressive loads applied while weightbearing in full extension following a vertical, longitudinal repair or bucket-handle repair have been shown to reduce the meniscus and stabilize the tear, as noted by Rodeo  and more recently by McCulloch.

Early Range of Motion After Meniscus Repair

What about early range of motion?

There is very limited literature on the influences of range of motion on meniscal movement. Thompson showed that during flexion, the posterior excursion of the medial meniscus was 5.1 mm, while that of the lateral meniscus was 11.2 mm.

Looking at meniscal movement as the knee flexes in weightbearing and non-weightbearing you can see there’s less motion, although I really don’t think we know how much motion is detrimental. The motion has been shown to help improve blood flow to the area. This is huge and may aid in the healing process!meniscus biomechanics

What Do We Recommend?

Anecdotally, I can say we have handled meniscal repairs to allow weightbearing and range of motion to tolerance for many years.  Some of the top orthopedic surgeons in the world that I have worked with currently handle a meniscal repair the same as an ACL reconstruction with a meniscal repair .

For an isolated meniscal repair, I prefer the knee continue to be immobilized in full extension for 4-6 weeks but allowed full weightbearing immediately (if a longitudinal repair). For complex repairs, I would recommend limiting weightbearing to partial but understand that the hoop stresses could aid in healing and are arguably helpful and necessary.  For both cases, I would recommend passive range of motion to tolerance.

Trust me, I respect the healing meniscus and continually monitor patients as I progress their range of motion and weight-bearing activities. Things like new joint line pain along the site of the repair, new swelling or a change in pain patterns, and even clicking (although most people have this) are all signs that I may want to further assess and modify my progression.

Based off of this, I continue to stand by my rehab guidelines of full, pain free passive range of motion and immediate weightbearing after a vertical longitudinal meniscal repair. The literature is screaming this same thing at us but we continue to ignore their calls and revert to the 90’s!

What do the surgeons that you work with recommend?  Are any of them still recommending rehab guidelines based on outdated research?  Comment below and let me know, I want to hear what the rest of the country is seeing!

Learn How I Evaluate and Treat the Knee

If you want to learn even more about meniscus rehabilitation, we discuss all of this this and much more in our online knee course at OnlineKneeSeminar.com where we teach you exactly how we evaluate and treat the knee.  Click below to learn more:

6 Keys to ACL Rehabilitation

The latest Inner Circle webinar recording on 6 Keys to ACL Rehabilitation is now available.

 

6 Keys to ACL Rehabilitation

6 keys to acl rehabilitationThis month’s Inner Circle webinar is on 6 Keys to ACL Rehabilitation.  In this presentation, I’ll go over the 6 key foundational principles that you need to understand to maximize your results with ACL rehab.  There are many surgical and patient variables that may speed up or slow down the standard rehab progression, however, you can build an optimal program by following these 6 principles.

This webinar will cover:

  • The #1 complication after ACL rehab, prolonged weakness, and how to minimize this
  • The two most important things to focus on during the first week of rehabilitation
  • How to develop advanced strength programs and alter periodization schemes in the rehab setting
  • My simple, yet effective, criteria to return to activities

 

To access this webinar:

 

OnlineKneeSeminar.com Bloopers!

Since I’m writing this on Friday the 13th, I thought it would be funny to share some bloopers from OnlineKneeSeminar.com, our program teaching you exactly how Lenny Macrina and I evaluate and treat the knee.  

It’s not as easy as everyone thinks to film these programs so Lenny and I wanted to share some quick bloopers from the filming!

Happy Friday the 13th!

Learn Exactly How I Evaluate and Treat the Knee

Want to learn even more about how I evaluate and treat the knee?  You still can!  My online program on the Recent Advances in the Evidence-Based Evaluation and Treatment of the Knee is now available.  I’ll show you everything you need to master the knee.  Click the button below for more information and to sign up now!
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The Best and Easiest Way to Restore Knee Extension

One of the most common complications following a knee injury or surgery is not restoring full knee extension.  Losing knee extension causes a lot of issues, ranging from anterior knee pain, to altered movement patterns, to even difficulty when walking.

It’s super important to assure you restore full knee extension.

In this video below, Lenny Macrina, my co-owner of Champion and co-author of OnlineKneeSeminar.com, shares what he considers the best way to restore full knee extension.  Luckily, it’s not only the best in our minds but also the easiest to perform!  More importantly, he discusses why he doesn’t like one of the most common exercises that people tend to use.

 

 

Learn Exactly How I Evaluate and Treat the Knee

Want to learn even more about how I evaluate and treat the knee?  My online program on the Recent Advances in the Evidence-Based Evaluation and Treatment of the Knee is now available.  I’ll show you everything you need to master the knee.  Click the button below for more information and to sign up now!

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The One Thing You Must Do When Evaluating for an ACL Injury

Anterior cruciate ligament (ACL) injuries are common. When evaluating the ACL, special tests like a Lachman Test or Anterior Drawer have been shown to have great reliability and validity.

However, there is one main reason why you may get a false positive for an ACL injury of the knee that is often overlooked – you actually injured your posterior cruciate ligament (PCL)!

I know, it seems backwards, but watch this quick video for my explanation!

 

Learn Exactly How I Evaluate and Treat the Knee

Want to learn even more about how I evaluate and treat the knee? My online program on the Recent Advances in the Evidence-Based Evaluation and Treatment of the Knee is now available. I’ll show you everything you need to master the knee.  Click the button below for more information and to sign up now!

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3 Tips for Assessing the Patellofemoral Joint

The latest Inner Circle recording on 3 Tips for Assessing the Patellofemoral Joint is now available.

3 Tips for Assessing the Patellofemoral Joint

3 Tips for Assessing the Patellofemoral Joint

This month’s Inner Circle presentation is on 3 Tips for Assessing the Patellofemoral Joint.  In this live inservice recording, I discuss a few tips that that I follow when evaluating someone with anterior knee pain, or patellofemoral pain syndrome.  Often times the patellofemoral joint gets little attention during the examination.  But, in order to treat patellofemoral pain successfully, you need to have an accurate diagnosis that is very specific.  Not all anterior knee pain is the same!

This presentation will cover:

  • How your anatomy of your trochlea can alter your ability to statically stabilize
  • How to assess the static stabilizers of the patella
  • A detailed overview of how I palpate different soft tissue structures around the knee
  • How and why you need to look both proximally and distally as well as at the knee
  • The one simple test I do with everyone to assess how proximal and distal factors xalter the forces at the knee

To access this webinar:

The Effect of Ipsilateral and Contralateral Loading on Muscle Activity During the Lunge

One thing I talk about a lot when it comes to training and rehabilitation is the need to train the body in all three planes.  This often requires moving in one plane of motion and stabilizing in the other two.   We are often very good at moving in the sagittal plane, and poor at stabilizing in the transverse and frontal planes.  This is a big topic of discussion in my program Functional Stability Training of the Lower Body.

To enhance this triplanar stability, we often attempt to facilitate greater contraction of the gluteus medius muscle during sagittal plane exercises.  The lunge in particular is a great exercise for triplanar stability as the narrow stance challenges strength in the sagittal plane and stability in the transverse and frontal planes.

 

The Effect of Ipsilateral and Contralateral Loading on Muscle Activity During the Lunge

The Effect of Ipsilateral and Contralateral Loading on Muscle Activity During the LungeA recent study was published in the Journal of Strength and Conditioning Research that investigated the effect of holding a dumbbell in either the contralateral or ipsilateral hand during a split squat and forward lunge.  (Note: they called it a “walking lunge” but I am 99% certain it was a forward lunge, so I’m just going to say forward lunger in this article…  probably just semantics.)

The study found that:

  • Holding the dumbbell on the ipsilateral side had no effect on glute med activity.
  • Holding the dumbbell on the contralateral side resulted in a significant increase in glute med activity, but only during the forward lunge, not the split squat.

I was a bit surprised that glute med activity was not impacted during the split squat, but perhaps the static nature of the position inherently requires less transverse and frontal plane stability.

There was one other finding from this study that I thought was interesting.  Kinematic differences during the forward lunge were found between a group of trained individuals in comparison to a group without training experience.

This makes sense as the forward lunge is a complex movement pattern that requires an understanding of how to control the pattern.  It requires both mobility and stability, but also the ability to control the eccentric deceleration phase.

contralateral lungeHowever, there were no kinematic differences between training age during the split squat, meaning that both novice and experienced trainees performed the split squat in a similar fashion.  This make split squats a great exercise to incorporate in the early phases of training for those with limited training experience, eventually progressing to forward lunge as they get better at moving and stabilizing the pattern.

This helps solidify the use of split squats in our lunge regression system.

 

Implications

I like simple studies like this.  Having the rationale to make small tweaks to your program is what sets you apart.  It’s the small things that may not be obvious at first but will produce better results over time.

Based on these results, I would recommend using the split squat with bilateral dumbbells to maximize strength gains since a unilateral load did not alter glute med activity.  The split squat is more of a basic exercise, so why not just use it to work on strength gains in the novice trainee.  As the person progresses, you can add the forward lunge variation with a contralateral load to enhance triplanar stability.

 

 

 

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